To me, there is a difference between wanting to dress nice, comb your hair neatly, look presentable, and having a positive self image through enhancing what you already have, compared to literally going under a knife, to physically alter your face/body permantely though.

One is in the realm of positive self image, and the other creeps into the realm of severe insecurities.

How about those balding men who go through hair implants?

I think the problem here is you're generalizing. Do some woman who go through plastic surgery have serious issues? sure. But there's the other half who don't have serious issues at all. Since plastic surgery is somewhat accepted and normal in our society, there must be a lot of women who think, "Hey, rather than live with this flat chin, why don't I just change it to the way I like. I have extra money anyway." Does that sound like a serious issue?